1. Field of the Invention
This invention relates generally to valves, and more particularly to a combination shut-off and test-injection valve having a shut-off valve portion for shutting off fluid flow through the valve body to isolate portions of the system in which it is installed and a test-injection portion which allows connection of test equipment, gauges, and injection devices for diagnosing and cleaning the system and its components.
2. Brief Description of the Prior Art
In diagnosing fuel and air systems of engines, it is often necessary isolate portions of the system and then to install various testing equipment, gauges, and injection devices to test and clean the fuel or air system and its components.
In order to carry out the diagnosing and servicing operations, the service technician must have on hand a large inventory of various adapters and fittings, particularly when servicing systems which are not provided with test ports. When connected, the adapters and fitting are prone to leakage which results in inaccurate readings, and safety hazards.
Maintaining an inventory of adapters and fittings necessary to access the various different systems of all the vehicles on the road today is a considerable financial expense. Many late model automobiles have fuel pumps and fuel pressure regulators which cannot be easily disabled. Locating the proper test points in the system and connecting the appropriate combination of adapters and fittings is also time consuming, thus labor and cost intensive. For these reasons, many mechanics and automotive shops will not provide this type of service.
It would therefore be desirable to provide a combination shut-off and test-injection valve which can be easily connected in nearly all fuel or air lines and will allow components and portions of fuel or air systems to be isolated and which has an integral test-injection fitting to allow connection of test equipment, gauges, and injection devices for diagnosing and cleaning the system and its components.
There are several patents which disclose various combination valves.
Krechel et al, U.S. Pat. No. 4,076,211 discloses a combination valve and manifold assembly for a compressed air storage tank or the like having a spherical ball valve rotatably disposed within a lateral bore of the valve body with circular sealing heads at each side of the ball portion to balance the pressure forces acting on the ball member which tend to move it axially. A seal body is received in the main flow passageway in one end of the valve body to sealingly engage the ball member after it has been installed in the lateral bore. The valve body has two outlet nipples at the inlet end for connection to a pressure gauge or pressure actuated switch for controlling operation of an air compressor. Each nipple has a tubular metal stiffener pressed therein. A safety pressure relief valve is provided in the manifold assembly for automatically relieving pressure from within the compressor tank upon exceeding a predetermined pressure level.
Heinen, U.S. Pat. No. 3,362,433 discloses a four-way plug valve which has a bleed valve connected to the valve bonnet in communication with the outer side of the plug member and a pressure relief valve connected to a bottom plate beneath the plug member.
The present invention is distinguished over the prior art in general, and these patents in particular by a combination shut-off and test-injection valve which has a shut-off valve and a test-injection valve in the valve body. The valve body has an inlet end and an outlet end adapted for connection to a fluid line or conduit and a fluid flow passageway extending from end to end. The shut-off valve in the body is movable between an open position allowing fluid flow through the body and a closed position closing off fluid flow through the body. The test-injection valve is in fluid communication with the fluid flow passageway adjacent the shut-off valve which is movable between a normally closed position preventing communication between the fluid flow passageway and the exterior of the body and an open position allowing fluid communication between the fluid flow passageway and the exterior of the body. The shut-off valve and the test-injection valve operate independently whereby the shut-off valve may be operated to open or close fluid flow through the valve body and isolate portions of the fluid system in which it is installed and the test-injection valve may be connected to test equipment, injection devices, and the like for diagnosing and cleaning the fluid system and its components during normal operating conditions or in an isolated condition. The combination valve may be left in the system after installation and will not interfere with normal operations as long as the shut-off valve remains open and will allow subsequent diagnosing and testing of the system and its components.